More from WebMD

Oct. 20, 2011 -- Doctors need to recommend the human papillomavirus (HPV) vaccine to help increase the number of girls getting immunized, according to CDC researchers.

Two vaccines against human papillomavirus, a common sexually transmitted infection, were licensed for use in the U.S. in 2006 and 2009. The vaccines target the main types of HPV that cause cervical cancer.

Each HPV vaccine consists of three doses, with the first two doses given one or two months apart (depending on which vaccine is given), and the third one given six months after the first.

In 2006, the CDC's Advisory Committee on Immunization Practices recommended that girls get vaccinated at age 11 or 12, before they become sexually active and are exposed to HPV.

The committee also recommended that older teens and women up to age 26 who haven't been fully vaccinated receive "catch-up" vaccinations.

But an analysis of 2008 and 2009 nationwide survey data found that only about 40% of girls 13 to 17 had received at least one dose of the vaccine, and only about half of those girls had received all three.

The study is published in Pediatrics.

"It's hard to say that I'm surprised, but it is concerning," says study researcher Christina Dorell, MD, MPH, a medical epidemiologist at the CDC.

Dorell says that vaccination coverage among teens 13 through 17 had risen since 2006. But the increases were greater for the Tdap (tetanus, diphtheria, and pertussis) and meningococcal vaccines than for the HPV vaccine.

Girls whose health care providers recommended the HPV vaccine were twice as likely to at least get the first dose as girls whose provider didn't make that recommendation, Dorell's new study found.

Role of Parents

About 27% of the parents of unvaccinated girls said they were not likely at all to get their daughters vaccinated in the next year, the study shows. Another 10% said they weren't sure.

Lack of knowledge about the HPV vaccine, the notion that it wasn't needed, and the belief that their daughters weren't sexually active were the main reasons that parents said they didn't plan to get them vaccinated.

Parents are used to taking babies and young children to the doctor for their immunizations, Dorell says, but "once you get to these teenage years, they're going to the doctor less frequently." And the fact that the HPV vaccine requires three trips to the doctor's office complicates matters, she says.

Dorell and co-researchers suggest that doctors schedule appointments for the second and third doses when parents bring their daughters in for the first and send out reminders for the upcoming visits.

Kristen Feemster, MD, agrees with Dorell about the importance of health care providers promoting HPV vaccination to parents. Feemster is an infectious disease specialist and health services researcher at the Children's Hospital of Philadelphia. She was not involved in Dorell's study

"If you don't have a strong recommendation from your provider, and you have any doubts at all, you're going to be less likely to walk into the room and say, 'I want my child to have this,'" Feemster says.

One big difference between the HPV vaccine and other childhood vaccines is that it protects against a disease, cervical cancer, that doesn't affect children, Feemster notes. "It doesn't feel quite as imperative."